From 2446ab6070861aba2dd9229463ffbc40016a9f33 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Thu, 1 Mar 2012 17:00:56 -0500 Subject: SUNRPC: Use RCU to dereference the rpc_clnt.cl_xprt field A migration event will replace the rpc_xprt used by an rpc_clnt. To ensure this can be done safely, all references to cl_xprt must now use a form of rcu_dereference(). Special care is taken with rpc_peeraddr2str(), which returns a pointer to memory whose lifetime is the same as the rpc_xprt. Signed-off-by: Trond Myklebust [ cel: fix lockdep splats and layering violations ] [ cel: forward ported to 3.4 ] [ cel: remove rpc_max_reqs(), add rpc_net_ns() ] Signed-off-by: Chuck Lever Signed-off-by: Trond Myklebust --- fs/nfs/callback_proc.c | 9 +++++---- fs/nfs/client.c | 16 +++++++++++----- fs/nfs/nfs4namespace.c | 2 +- fs/nfs/nfs4proc.c | 13 ++++++++++--- fs/nfs/nfs4state.c | 25 +++++++++++++++++-------- fs/nfs/super.c | 5 +++++ 6 files changed, 49 insertions(+), 21 deletions(-) (limited to 'fs/nfs') diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c index 0e0865e3806..1bb29724362 100644 --- a/fs/nfs/callback_proc.c +++ b/fs/nfs/callback_proc.c @@ -8,6 +8,7 @@ #include #include #include +#include #include "nfs4_fs.h" #include "callback.h" #include "delegation.h" @@ -33,7 +34,7 @@ __be32 nfs4_callback_getattr(struct cb_getattrargs *args, res->bitmap[0] = res->bitmap[1] = 0; res->status = htonl(NFS4ERR_BADHANDLE); - dprintk("NFS: GETATTR callback request from %s\n", + dprintk_rcu("NFS: GETATTR callback request from %s\n", rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR)); inode = nfs_delegation_find_inode(cps->clp, &args->fh); @@ -73,7 +74,7 @@ __be32 nfs4_callback_recall(struct cb_recallargs *args, void *dummy, if (!cps->clp) /* Always set for v4.0. Set in cb_sequence for v4.1 */ goto out; - dprintk("NFS: RECALL callback request from %s\n", + dprintk_rcu("NFS: RECALL callback request from %s\n", rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR)); res = htonl(NFS4ERR_BADHANDLE); @@ -533,7 +534,7 @@ __be32 nfs4_callback_recallany(struct cb_recallanyargs *args, void *dummy, if (!cps->clp) /* set in cb_sequence */ goto out; - dprintk("NFS: RECALL_ANY callback request from %s\n", + dprintk_rcu("NFS: RECALL_ANY callback request from %s\n", rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR)); status = cpu_to_be32(NFS4ERR_INVAL); @@ -568,7 +569,7 @@ __be32 nfs4_callback_recallslot(struct cb_recallslotargs *args, void *dummy, if (!cps->clp) /* set in cb_sequence */ goto out; - dprintk("NFS: CB_RECALL_SLOT request from %s target max slots %d\n", + dprintk_rcu("NFS: CB_RECALL_SLOT request from %s target max slots %d\n", rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR), args->crsa_target_max_slots); diff --git a/fs/nfs/client.c b/fs/nfs/client.c index 1506adf4d4e..d038dc5916e 100644 --- a/fs/nfs/client.c +++ b/fs/nfs/client.c @@ -1284,16 +1284,18 @@ static int nfs4_init_callback(struct nfs_client *clp) int error; if (clp->rpc_ops->version == 4) { + struct rpc_xprt *xprt; + + xprt = rcu_dereference_raw(clp->cl_rpcclient->cl_xprt); + if (nfs4_has_session(clp)) { - error = xprt_setup_backchannel( - clp->cl_rpcclient->cl_xprt, + error = xprt_setup_backchannel(xprt, NFS41_BC_MIN_CALLBACKS); if (error < 0) return error; } - error = nfs_callback_up(clp->cl_mvops->minor_version, - clp->cl_rpcclient->cl_xprt); + error = nfs_callback_up(clp->cl_mvops->minor_version, xprt); if (error < 0) { dprintk("%s: failed to start callback. Error = %d\n", __func__, error); @@ -1678,7 +1680,7 @@ struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *data, data->addrlen, parent_client->cl_ipaddr, data->authflavor, - parent_server->client->cl_xprt->prot, + rpc_protocol(parent_server->client), parent_server->client->cl_timeout, parent_client->cl_mvops->minor_version, parent_client->net); @@ -1905,12 +1907,14 @@ static int nfs_server_list_show(struct seq_file *m, void *v) if (clp->cl_cons_state != NFS_CS_READY) return 0; + rcu_read_lock(); seq_printf(m, "v%u %s %s %3d %s\n", clp->rpc_ops->version, rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR), rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_PORT), atomic_read(&clp->cl_count), clp->cl_hostname); + rcu_read_unlock(); return 0; } @@ -1993,6 +1997,7 @@ static int nfs_volume_list_show(struct seq_file *m, void *v) (unsigned long long) server->fsid.major, (unsigned long long) server->fsid.minor); + rcu_read_lock(); seq_printf(m, "v%u %s %s %-7s %-17s %s\n", clp->rpc_ops->version, rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_HEX_ADDR), @@ -2000,6 +2005,7 @@ static int nfs_volume_list_show(struct seq_file *m, void *v) dev, fsid, nfs_server_fscache_state(server)); + rcu_read_unlock(); return 0; } diff --git a/fs/nfs/nfs4namespace.c b/fs/nfs/nfs4namespace.c index 667ea7406fd..9c8eca315f4 100644 --- a/fs/nfs/nfs4namespace.c +++ b/fs/nfs/nfs4namespace.c @@ -96,8 +96,8 @@ static int nfs4_validate_fspath(struct dentry *dentry, static size_t nfs_parse_server_name(char *string, size_t len, struct sockaddr *sa, size_t salen, struct nfs_server *server) { + struct net *net = rpc_net_ns(server->client); ssize_t ret; - struct net *net = server->client->cl_xprt->xprt_net; ret = rpc_pton(net, string, len, sa, salen); if (ret == 0) { diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 6c8e170e2e6..671510cc14c 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -3833,6 +3833,7 @@ int nfs4_proc_setclientid(struct nfs_client *clp, u32 program, *p = htonl((u32)clp->cl_boot_time.tv_nsec); for(;;) { + rcu_read_lock(); setclientid.sc_name_len = scnprintf(setclientid.sc_name, sizeof(setclientid.sc_name), "%s/%s %s %s %u", clp->cl_ipaddr, @@ -3849,6 +3850,7 @@ int nfs4_proc_setclientid(struct nfs_client *clp, u32 program, setclientid.sc_uaddr_len = scnprintf(setclientid.sc_uaddr, sizeof(setclientid.sc_uaddr), "%s.%u.%u", clp->cl_ipaddr, port >> 8, port & 255); + rcu_read_unlock(); status = rpc_call_sync(clp->cl_rpcclient, &msg, RPC_TASK_TIMEOUT); if (status != -NFS4ERR_CLID_INUSE) @@ -5244,11 +5246,16 @@ struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp) void nfs4_destroy_session(struct nfs4_session *session) { + struct rpc_xprt *xprt; + nfs4_proc_destroy_session(session); + + rcu_read_lock(); + xprt = rcu_dereference(session->clp->cl_rpcclient->cl_xprt); + rcu_read_unlock(); dprintk("%s Destroy backchannel for xprt %p\n", - __func__, session->clp->cl_rpcclient->cl_xprt); - xprt_destroy_backchannel(session->clp->cl_rpcclient->cl_xprt, - NFS41_BC_MIN_CALLBACKS); + __func__, xprt); + xprt_destroy_backchannel(xprt, NFS41_BC_MIN_CALLBACKS); nfs4_destroy_slot_tables(session); kfree(session); } diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index c1111a37dc1..bae959e294c 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -1037,19 +1037,28 @@ static void nfs4_clear_state_manager_bit(struct nfs_client *clp) void nfs4_schedule_state_manager(struct nfs_client *clp) { struct task_struct *task; + char buf[INET6_ADDRSTRLEN + sizeof("-manager") + 1]; if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0) return; __module_get(THIS_MODULE); atomic_inc(&clp->cl_count); - task = kthread_run(nfs4_run_state_manager, clp, "%s-manager", - rpc_peeraddr2str(clp->cl_rpcclient, - RPC_DISPLAY_ADDR)); - if (!IS_ERR(task)) - return; - nfs4_clear_state_manager_bit(clp); - nfs_put_client(clp); - module_put(THIS_MODULE); + + /* The rcu_read_lock() is not strictly necessary, as the state + * manager is the only thread that ever changes the rpc_xprt + * after it's initialized. At this point, we're single threaded. */ + rcu_read_lock(); + snprintf(buf, sizeof(buf), "%s-manager", + rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR)); + rcu_read_unlock(); + task = kthread_run(nfs4_run_state_manager, clp, buf); + if (IS_ERR(task)) { + printk(KERN_ERR "%s: kthread_run: %ld\n", + __func__, PTR_ERR(task)); + nfs4_clear_state_manager_bit(clp); + nfs_put_client(clp); + module_put(THIS_MODULE); + } } /* diff --git a/fs/nfs/super.c b/fs/nfs/super.c index f4ccdae6a0c..7002be11d99 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -53,6 +53,7 @@ #include #include #include +#include #include #include @@ -701,8 +702,10 @@ static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss, else seq_puts(m, nfs_infop->nostr); } + rcu_read_lock(); seq_printf(m, ",proto=%s", rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID)); + rcu_read_unlock(); if (version == 4) { if (nfss->port != NFS_PORT) seq_printf(m, ",port=%u", nfss->port); @@ -751,9 +754,11 @@ static int nfs_show_options(struct seq_file *m, struct dentry *root) nfs_show_mount_options(m, nfss, 0); + rcu_read_lock(); seq_printf(m, ",addr=%s", rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient, RPC_DISPLAY_ADDR)); + rcu_read_unlock(); return 0; } -- cgit v1.2.3